An aircraft includes a fuselage having an upper surface and a lower surface that define an airfoil shape in cross-section along a vertical plane such that horizontal movement of the fuselage through air produces a lift force in a vertical direction. The aircraft also includes a plurality of modules attached to the fuselage. Each module includes an upper jet engine directed above the upper surface of the fuselage and an opposed lower jet engine directed below the lower surface of the fuselage.

An aircraft includes a fuselage having an upper surface and a lower surface that define an airfoil shape in cross-section along a vertical plane such that horizontal movement of the fuselage through air produces a lift force in a vertical direction. The aircraft also includes a plurality of modules attached to the fuselage. Each module includes an upper jet engine directed above the upper surface of the fuselage and an opposed lower jet engine directed below the lower surface of the fuselage.

Embodiments in accordance with the invention address potential co-orbital threats to a spacecraft through the use of a plurality of evasion pattern maneuvers selected to prevent a rendezvous with a potential co-orbital threat from occurring within a finite horizon. Embodiments in accordance with the invention maintain separation from the potential co-orbital threat while minimizing a defending spacecraft's fuel consumption.

A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.

A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.

Systems and methods for satellite orbit and momentum control are disclosed herein. An example spacecraft includes a first arm having a first end pivotably coupled to the spacecraft and a second end. The example spacecraft includes a first thruster rotatably coupled to the second end of the first arm. The first arm is to selectively pivot about the spacecraft to position the first thruster to generate a change in velocity of the spacecraft to maintain the spacecraft within an orbit station.

Systems and methods for satellite orbit and momentum control are disclosed herein. An example spacecraft includes a first arm having a first end pivotably coupled to the spacecraft and a second end. The example spacecraft includes a first thruster rotatably coupled to the second end of the first arm. The first arm is to selectively pivot about the spacecraft to position the first thruster to generate a change in velocity of the spacecraft to maintain the spacecraft within an orbit station.

A Fiber-fed Pulsed Plasma Thruster (FPPT) utilizes a motor to feed PTFE fiber to its discharge region, enabling high PPT propellant throughput and variable exposed fuel area. A highly parallel ceramic capacitor bank lowers system specific mass. Impulse bits (I-bits) from 0.057-0.241 mN-s have been measured on a thrust stand with a specific impulse (Isp) of 900-2400 s, representing an enhancement from state-of-the-art PPT technology. A 1 U (10 cm×10 cm×10 cm, or 1 liter) volume FPPT thruster package will provide 2900-7700 N-s total impulse, enabling 0.6-1.6 km/s delta-V for a 5 kg CubeSat. A 1 U design variation with 590 g propellant enables as much as .sup.˜10,000 N-s and a delta-V of 2 km/s for a 5 kg CubeSat. Increasing the form factor to 2U increases propellant mass to 1.4 kg and delta-V to 10.7 km/s for an 8 kg CubeSat.

Cryogenic propellant tank (1) for a spacecraft engine, comprising an external enclosure (10) defining an internal volume, characterized in that the internal volume of the tank comprises a primary volume (V1) and a secondary volume (V2) connected to the primary volume (V1) via a valve (20) configured to selectively allow a passage of fluid from the primary volume (V1) to the secondary volume (V2), or to isolate the secondary volume (V2) from the primary volume (V1), the primary volume (V1) having a primary orifice (11) adapted to be connected to a first pressurization source (41), the secondary volume (V2) having a supply orifice (4) adapted to be connected to a supply line of a spacecraft engine (30), and a secondary orifice (12) adapted to be connected to a second pressurization source (42).

Apparatus and methods for controlling a spacecraft for a transfer orbit. The spacecraft includes a momentum subsystem that stores angular momentum relative to a center of mass of the spacecraft, and a propulsion subsystem that includes electric thrusters. A controller identifies a target spin axis for the spacecraft, determines gimbal angles for electric thruster(s) that so that thrust forces from the electric thrusters are parallel to the target spin axis, and initiates a burn of the electric thruster(s) at the gimbal angles. The controller controls the momentum subsystem to compensate for a thruster torque produced by the burn of the electric thrusters. The momentum subsystem is able to produce a target angular momentum about the center of mass, where a coupling between the target angular momentum and an angular velocity of the spacecraft creates an offset torque to counteract the thruster torque.